Growing of bulk β-(Al x Ga1-x )2O3 crystals from the melt by Czochralski method and investigation of their structural and optical properties

Bulk (Al x Ga1-x )2O3 crystals with an Al fraction x in the range from 0.0 to 0.23 were successfully grown by the Czochralski method. An increase in the band gap from 4.7 eV to 5.1 eV with the rise of the Al content was demonstrated by analyzing optical transmission spectra. The crystal quality of the obtained samples was controlled by X-ray diffractometry. The appearance of crystal`s mosaic blockness was found for the Al fraction x above 0.05.

Спектральные и рентгеновские исследования пленок оксида индия на сапфировых подложках

The results of investigation of optical transmission spectra and X-ray diffraction of thin In2O3 films deposited by dc-magnetron sputtering on Al2O3 (012) substrates are presented. The diffraction patterns exhibit the presents of the (222) reflex of cubic In2O3. Its position shifts from 30.3 to 30.6°, with a decrease in the film thickness. There was also a decrease in the half-width of this reflex by a decrease in the deposition time, which may indicate an increase in the crystallite size of the film material. According to the optical transmission measurements, the presence of a transition layer with the band gap of 1.39 eV and about of 40 nm thickness was established at the interface between the film and substrate. The properties of this layer are independent of the deposition time.

Выращивание объемных кристаллов оксида галлия из расплава методом Чохральского в кислородсодержащей атмосфере

This paper reports on successful experiments in growing beta-gallium oxide crystals using the Czochralski method. The influence of growth atmosphere composition on crystal quality of the material was studied. It is shown that to obtain high quality optically transparent crystals it is necessary to have about 5 vol.% oxygen in the growth atmosphere. X-ray structural analysis and investigation of optical transmission spectra of grown crystals are carried out.

Оптические свойства пленок ниобата бария стронция SBN61

Heteroepitaxial Sr_0.61Ba_0.39Nb_2O_6 films have been formed on MgO(001) substrates by RF deposition in an oxygen atmosphere. The film orientation with respect to the substrate is investigated using X-ray diffraction. The permittivity dispersion parameters in the visible range are determined by measuring optical transmission spectra. The films are found to have a wider band gap and a smaller refractive index as compared with the single-crystal material.